Security Architecture

Security Architecture Documentation

🏗️ Overview

SecureBit.chat implements a 12-layer security architecture exceeding military standards.

🔐 Cryptographic Stack

Layer 1: Transport Security (WebRTC DTLS)

• Protocol: DTLS 1.2/1.3
• Cipher Suites: ECDHE-RSA-AES256-GCM-SHA384
• Key Exchange: ECDHE with P-256/P-384 curves
• Purpose: Secure transport layer

Layer 2: Key Exchange (ECDH P-384)

• Algorithm: Elliptic Curve Diffie-Hellman
• Curve: P-384 (NIST curve)
• Security Level: 192-bit equivalent
• Purpose: Perfect forward secrecy

Layer 3: Message Encryption (AES-GCM 256)

• Algorithm: AES-GCM
• Key Size: 256-bit
• Mode: Galois/Counter Mode
• Purpose: Authenticated encryption

Layer 4: Digital Signatures (ECDSA P-384)

• Algorithm: ECDSA
• Curve: P-384
• Purpose: Message integrity and authenticity

Layer 5: Replay Protection

• Mechanism: Timestamp validation
• Window: ±30 seconds
• Purpose: Prevent replay attacks

Layer 6: Key Rotation

• Interval: Every 5 minutes or 100 messages
• Method: Automatic re-keying
• Purpose: Limit exposure window

Layer 7: MITM Protection

• Method: Out-of-band verification
• Codes: 6-character alphanumeric
• Purpose: Prevent man-in-the-middle attacks

Layer 8: Traffic Obfuscation

• Method: Fake traffic generation
• Pattern: Random intervals
• Purpose: Defeat traffic analysis

Layer 9: Metadata Protection

• Method: Zero metadata leakage
• Storage: No persistent data
• Purpose: Complete privacy

Layer 10: Memory Protection

• Method: No persistent storage
• Cleanup: Complete session cleanup
• Purpose: Prevent data extraction

Layer 11: Hardware Security

• Method: Non-extractable keys
• Storage: Secure enclave (when available)
• Purpose: Key protection

Layer 12: Session Isolation

• Method: Complete session cleanup
• Scope: All session data
• Purpose: Prevent cross-session attacks

�� Security Standards Compliance

NIST Standards

• SP 800-56A: Key Agreement
• SP 800-186: Elliptic Curve Cryptography
• SP 800-38D: GCM Mode

RFC Standards

• RFC 6090: Fundamental ECC Algorithms
• RFC 8446: TLS 1.3
• RFC 5116: Authenticated Encryption

🔍 Security Analysis

Threat Model

1. Passive eavesdropping: Mitigated by encryption
2. Active interception: Mitigated by MITM protection
3. Traffic analysis: Mitigated by obfuscation
4. Key compromise: Mitigated by rotation
5. Session hijacking: Mitigated by isolation

Attack Vectors

• Network attacks: Protected by DTLS
• Application attacks: Protected by code isolation
• Physical attacks: Protected by memory cleanup
• Social engineering: Mitigated by verification codes